Comment Letter: Deny Petition that seeks to add dams and reservoirs as MRR Reporting Entities

Agency: California Air Resources Board

Subject: Deny Petition that seeks to add dams and reservoirs as MRR Reporting Entities and repeal hydropower exemption

Letter excerpt:

The Association of California Water Agencies respectfully requests that the California Air Resources Board (CARB) deny the petition filed by Tell the Dam Truth, Patagonia, and co-petitioners on March 25, 2026 (Petition) seeking to designate dams and reservoirs as reporting entities under the Mandatory Greenhouse Gas Reporting Regulation (MRR) and repeal the existing hydropower exemption. ACWA represents approximately 470 public water agencies that collectively deliver approximately 90 percent of the water in California for domestic, agricultural, and industrial uses. Dams and reservoirs are an essential component of maintaining water resources for broad use across the state, and hydropower serves as one of California's most reliable low carbon power sources. This Petition seeks to challenge core water infrastructure without fully considering the value it provides to the state. We have numerous concerns with the Petition, will lay out these concerns to walk through our reasoning to deny this Petition, and will offer potential next steps for CARB's consideration.

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